Chem Lab Midterm (not part of experiment)

Question 0

I Sulfate Group includes

Answer 0

SO4
HCO3
PO4

Question 1

Anions are grouped as

Answer 1

II Sulfate Group
II Halide Group
III Nitrate Group

Question 2

II Halide Group includes

Answer 2

Cl
Br
I
S

Question 3

III Nitrate Group Includes

Answer 3

NO3

Question 4

In ______ solutions only anions of Group I are precipitated by _____

Answer 4

Ammoniacal

Ba

Question 5

In ____ solutions only anions of group II are precipitated with _____

Answer 5

HNO3

Ag

Question 6

Reagents of Group I Sulfate anions

Answer 6

NH3

BaCl2

Question 7

Reagents of Group II Halide ions

Answer 7

HNO3

AgNO3

Question 8

Reagent for Group III Nitrate ions

Answer 8

NO REAGENT

for all anions of this group are soluble

Question 9

Anions are divided into 4 groups on basis of

Answer 9

Their reactions with dilute HCl

Solubilities of their Ba and Ag salts

Question 10

What are the 4 divisions of anions?

Answer 10

I. Visible change, gas evolution and/or formation of a precipitate with dilute HCl

II. Do not react with HCl but forms precipitates with Ba ions in neutral medium

III. Do not react with either Ba ions or HCl in neutral medium

IV. Common anions which do not react with reagents of the previous groups

Question 11

Anions of division I

Answer 11

HCO3
Silicate
Sulphide
Sulphite
Thiosulfate

Question 12

Anions of division II

Answer 12

Sulphate
Phosphate
Fluoride
Borate

Question 13

Anions of Division III

Answer 13

Chloride
Bromide
Iodide
Thiocyanate

Question 14

Anions of Division IV

Answer 14

NO3
NO2
Chlorate ions

Question 15

Only anion in group I that forms a strong acid

Answer 15

Sulfate

Question 16

It is insoluble in HCl

Answer 16

BaSO4

Question 17

All barium salts of this group dissolve in strong acid

Answer 17

Group I

Question 18

Test for sulfate ion

Answer 18

Addition of HCl and BaCl2

Question 19

BaSO4 produces a _____ precipitate

Answer 19

White

Question 20

It is stable only in basic solutions

Answer 20

Sulfide

Question 21

Sulfide + acid =

Answer 21

H2S gas

Question 22

When H2S gas comes in contact with moist Pb(Ac)2 filter paper it forms ________

Answer 22

Black Lead Sulfide

Question 23

Hydrogen Sulfide has a _______ odor

Answer 23

Rotten egg

Question 24

Sulfide ion can be destroyed by reaction with strong oxidizing agents such as ______ or ______

Answer 24

Sulfite ion | HNO3

Question 25

All _____ salts are soluble

Answer 25

Nitrate

Question 26

It has no precipitation test

Answer 26

Nitrate

Question 27

Test for nitrate ions that involve reduction by ferrous ion in concentrated H2SO4

Answer 27

Brown-ring test

Question 28

What forms the brown ring during a brown ring test?

Answer 28

Nitric oxide complexes with excess ferrous ion | FeNO2 = brown-ring

Question 29

It is essential that an excess of _____ be used and that concentrated _____ is used in a brown ring test.

Answer 29

Ferrous ion | H2SO4

Question 30

Nitrate test

Answer 30

Brown-ring test

Question 31

Interferences of nitrate test

Answer 31

Presence of • Bromide • Iodide The conc. H2SO4 will oxidize the halide ion to the free halogen, giving a false positive color.

Question 32

It is a moderately weak, non- volatile acid

Answer 32

Phosphate

Question 33

Phosphate ions precipitate by reaction with ______

Answer 33

Ammonium Molybdate

Question 34

PO4 + ammonium molybdate =

Answer 34

Yellow precipitate | Mixed salt, AMMONIUM PHOSPHOMOLYBDATE

Question 35

Interference in phosphate test

Answer 35

Presence of sulfide ions

Question 36

How to get rid of sulfide ions during phosphate test

Answer 36

Acidify solution with HCl and then boil it

Question 37

They are like sulfate ions - they are also ions of strong acids

Answer 37

* Chloride * Bromide * Iodide

Question 38

* Chloride * Bromide * Iodide Form _____ with Ag ion in HNO3

Answer 38

Insoluble salts

Question 39

What color is Silver Chloride AgCl

Answer 39

White

Question 40

What color is AgBr?

Answer 40

Pale yellow ( slightly soluble in ammonia solution)

Question 41

What color is AgI ?

Answer 41

Yellow ( does not dissolve in ammonia)

Question 42

These ions can be confirmed by oxidation with free Cl and generating free Br or I.

Answer 42

Bromide | Iodide

Question 43

They are more soluble in hexane that in H2O and take on a distinctive color

Answer 43

Free halogens

Question 44

What color is Bromide?

Answer 44

Reddish-brown

Question 45

What color is Iodide?

Answer 45

Violet

Question 46

It forms a weak acid, carbonic acid

Answer 46

Carbonate

Question 47

It is not very soluble and breaks down forming H2O and CO2

Answer 47

Carbonic Acid

Question 48

It confirms the presence of carbonate ions

Answer 48

Effervescence

Question 49

A colorless and odorless gas released when a carbonate ion is present

Answer 49

Effervescence

Question 50

______ + carbonate solution = effervescence

Answer 50

Strong acid

Question 51

What group forms precipitate with Ag ions in dilute HNO3 medium?

Answer 51

Group III